The regulation of the temperature of electronic components like processors due to heat generated inside the casing of an electronic device like a blade server is an important consideration during the design of an electronic device. Cooling is critical because if left unchecked, heat can cause electronic devices to malfunction during use or led to premature device failure. As improvements in processor clock speed occur, the amount of heat generated by the faster processors also increases. Additionally, improved processors require larger power supplies and auxiliary components that generate increased amounts of heat and require improved sophisticated systems for heat removal.
Another factor that aggravates the need for improved heat removal cooling systems is the trend towards making computing devices such as blade servers smaller and especially thinner. The trend toward smaller and thinner electronic devices having larger, faster processors renders the traditional heat removal cooling systems inadequate for several reasons. First, smaller devices having faster processors result in an increased density of heat producing by electronic components leading to higher heat flux. Second, a decreased amount of space is available for temperature regulating devices such as traditional heatsinks. Lastly, a decreased amount of space is available to create ventilation paths that pass through the heat-exchanging channels of the heatsink. Thus, traditional cooling systems with blower assembly having one blower with an inlet that ventilates the entire housing of the device and, accordingly, all electronic components are less effective or inapplicable for removing heat when used in smaller, thinner devices.
There are numerous designs trend of coolers for cooling of electronic components that include one common heatsink installed in the contact with at least two electronic devices. These coolers have usually one common blower.
The heatsink of such cooler should have full tight contact with the surfaces of all electronic components. But it is difficult to insure that every electronic component will be coupled to the heatsink evenly because of linear and angular dimensional tolerances from one electronic component to another. Some of them may not even be coupled at all to the heatsink, while excessive mechanical stress may be imparted to the others.
There have been proposed a number of solutions in the past tried to solve these problems. One such solution, described in U.S. Pat. No. 4,235,283 “Multi-stud thermal conduction module” employs captive pistons or other elements with springs within the heatsink to contact the electronic component and accommodate variances in the mechanical features and tolerances. This technique is mechanically complex and therefore costly.
Another technique described in U.S. Pat. No. 5,981,310 “Multi-chip heat-sink cap assembly” employs the use of thermally conductive material as solder or a thermal compound to fill the gaps between the electronic components and the heatsink. This technique is difficult to implement, and it does not give good enough contact between the heatsinks and electronic components.
It is known solution described in U.S. Pat. No. 5,184,211 “Apparatus for packaging and cooling integrated circuit chips” that employs cushions from elastic material between each of the electronic components and the heatsink.
This solution and all other solutions with one common heatsink for several electronic components have one common disadvantage—they cannot provide a good tight reliable interface contact with low thermal resistance between the heatsinks and electronic components compared to the separate heatsinks that are individually installed and tightened on each electronic component.
It is known the solution described in U.S. patent application Ser. No. 10/488,797 Edward Lopatinsky et al. This solution includes at least one heat-exchange element, at least one heat-spreading element as a heat pipe with an adapter and the blower. However this is an indirect cooling solution, needs to be much more space with the heat pipes located between the adaptor and the heatsink.
It is also known design for direct cooling described in U.S. patent application Ser. No. 10/696,617 Edward Lopatinsky et al. There are two separate heatsinks individually attached to the each electronic component. On the top of the heatsinks there is attached the integrated radial blower hydraulically connected to the both heatsinks from the inlet part of the blower. It is much better solution in terms of lower thermal interface resistance between electronic components and heatsinks; however there is a disadvantage for such cooling system.
The height or thickness of the solution is the sum of the heatsink and the blower sizes that is preventing to produce such designs in the lower thickness. There is another disadvantage of such systems based on the lack of thermal contact between heatsinks. These electronic devices almost never work simultaneously at the highest clock speed; therefore they would not create the highest possible heat at the same time. Since heatsinks are thermally separated, there is no temperature equalizing from one to another heatsink. In this case the heat cannot equally distribute between both heatsinks that obviously negatively affects the overall cooling performance.
It would be desirable to provide a multi-heatsink integrated cooling device that overcomes these problems associated with insufficient thermal efficiency at smaller sizes.